Catálogo de publicaciones - revistas

<jats:p>Reports from the ongoing pandemic highlighted the entries</jats:p>

<jats:p> Highlights from the <jats:italic>Science</jats:italic> family of journals </jats:p>

<jats:p>Editors’ selections from the current scientific literature</jats:p>

<jats:title>A tunnel between RNA polymerases</jats:title> <jats:p> Eukaryotes encode five multiple-subunit, DNA-dependent RNA polymerases, of which Pol I, Pol II, and Pol III function as single units to produce cellular single-stranded RNA. The plant-specific Pol IV forms a complex with RDR2 (an RNA-dependent RNA polymerase) to produce double-stranded precursors of small interfering RNA essential for genomic DNA methylation. Huang <jats:italic>et al</jats:italic> . determined the cryo–electron microscopy structures of the Pol IV-RDR2 complex. The structures show that Pol IV and RDR2 connect their active centers through an inner RNA transfer channel and that Pol IV reverses transcription direction and hands over its transcript directly through the channel to RDR2 for the production of the second strand of the double-stranded RNA. —DJ </jats:p>

<jats:title>Path to another drug against COVID-19</jats:title> <jats:p> The rapid development of vaccines has been crucial in battling the ongoing COVID-19 pandemic. However, access challenges remain, breakthrough infections occur, and emerging variants present increased risk. Developing antiviral therapeutics is therefore a high priority for the treatment of COVID-19. Some drug candidates in clinical trials act against the viral RNA-dependent RNA polymerase, but there are other viral enzymes that have been considered good targets for inhibition by drugs. Owen <jats:italic>et al</jats:italic> . report the discovery and characterization of a drug against the main protease involved in the cleavage of polyproteins involved in viral replication. The drug, PF-07321332, can be administered orally, has good selectivity and safety profiles, and protects against infection in a mouse model. In a phase 1 clinical trial, the drug reached concentrations expected to inhibit the virus based on in vitro studies. It also inhibited other coronaviruses, including severe acute respiratory syndrome coronavirus 1 and Middle East respiratory syndrome coronavirus, and could be in the armory against future viral threats. —VV </jats:p>

<jats:title>Boosting ammonia with a little oxygen</jats:title> <jats:p> Ammonia synthesis from nitrogen for fertilizer production is highly energy intensive. Chemists are therefore exploring electrochemical approaches that could draw power from renewable sources while generating less waste. One promising cycle involves the reduction of lithium ions at an electrode, with the resultant metal in turn reducing nitrogen and regenerating the ions. Li <jats:italic>et al</jats:italic> . report the counterintuitive result that small quantities of oxygen could enhance the efficiency of this process, which they attribute to diffusional effects that limit excessive lithium reduction. —JSY </jats:p>

<jats:title>Stable but not quite cubic</jats:title> <jats:p> The black, photoactive phase of formamidinium (FA) perovskites, which is usually stabilized by cation alloying to avoid the formation of inactive hexagonal phases, is assumed to be cubic. High-resolution microscopy studies by Doherty <jats:italic>et al</jats:italic> . using nanoscale probes revealed that these FA-rich phases are not cubic but rather undergo slight tilting (by two degrees) of the octahedra. Black phases can have localized regions of hexagonal phases that nucleate degradation. Surface-bound ethylenediaminetetraacetic acid stabilized the tilted phase of pure FA lead triiodide against environmental degradation. —PDS </jats:p>